A man whose father has been missing for seven weeks has told how he is dreading the thought of spending his first ever Christmas without him.

John Concannon (71) who suffers from dementia and other health problems got on the wrong bus home on November 7.

He was last seen getting off the bus in the Lenamore Road area of Londonderry, near the border with Co Donegal.

His son Edward Concannon fears he may have wandered off in a confused state, and seven weeks of intense searching in both Derry and Donegal have so far failed to find the missing pensioner.

Edward and his brother Jonathan remain optimistic that their father will still be located and say it is the only way they can face getting out of bed.

Edward said: "I cannot give up hope my father will be found, but it is extraordinarily tough.

"This is the first Christmas we have spent without him and I am dreading it. I don't know what we are going to do.

"I have never suffered from depression in my life, but it is hard for me to get out of bed and keep going day after day. But I have to keep going - I am not ready to give up.

"I am so worried. I imagine how scared and confused he would have been after he got off the bus which wasn't the one that would have left him near our home. I can't stand to think about him going through such a traumatic time. I just want him home."

Police on both sides of the border have intensified their searches using specialist equipment in the hope that they can locate Mr Concannon. The last confirmed sighting of him was on CCTV footage on the bus at Lenamore Road, some distance away from his home in the Galliagh area of Derry.

Chief Inspector Alan Hutton, operations manager for Derry City and Strabane District, said the PSNI was working hand in glove with counterparts in the Republic to locate Mr Concannon.

He added: "This has been a joint effort, and we are also very appreciative of the contributions of a civilian community search team that has assisted.

"The information we have at this stage suggests a search area on and close to the border at Lenamore Road and across into Dundreen and Drumadooey.

"We will be renewing the searches and will be using specialist search facilities.

"In the meantime, our thoughts are with the Concannon family. They are going through a lot of uncertainty at a time of year when families like to be together.

"I want to thank everyone who has given information so far. I would encourage anyone who thinks they may have seen Mr Concannon, on either side of the border, to get in touch with their nearest police or Garda station."

Mr Concannon is described as being about 5ft 6in tall, of medium build and with grey hair.

At the time of his disappearance he was wearing a black and grey beanie hat, a black coat, checked shirt and navy trousers.